The cocktail starts to be interesting. Using the instruments of the robot Curiosity Mars , scientists have for the first time detected nitrogen on the surface of Mars in nitrate (NO3), an essential element for life, NASA said Tuesday.

Nitrates are a class of molecules that contain nitrogen in a form that can be used by living organisms, said the US space agency. This discovery thus provides further evidence that the Red Planet has in the past met the conditions for the existence of life.

Key building block for DNA

Nitrogen is essential to all known forms of life, as a key element of larger molecules such as DNA, that encodes the genetic instructions of life. On Earth as Mars, nitrogen is a gas in the atmosphere in the form of two atoms bound together which thus can not easily be combined with other molecules.

Or the nitrogen atoms to be alone or attached to oxygen molecules in order to create the chemical reactions necessary for life.

A molecule nitrate, formed of a nitrogen atom and three atoms of oxygen, is the fixed nitrogen source which can be combined with a variety of other atoms and molecules.

No evidence has been obtained from a living organism

However, the scientists point out that there is no evidence suggesting that the nitrate molecules discovered by an instrument Curiosity come from a living organism. The surface of Mars today is inhospitable to any known form of life.

According to these researchers, these nitrates are old and were the result of non-biological processes such as the asteroid impact or lightning on Mars in the distant past.

The scientific team Curiosity has found evidence proving that life could exist on Mars there are several billion years, such as the presence of abundant liquid water, as evidenced from ancient riverbeds and presence of organic materials in the crater Gale, where the robot landed in August 2012. After a short circuit in early March, the little robot successfully took over the road this week.